Hydraulic pump



noemer nsNAnL'r rE'LrEnIE, or rams, FRANCE.

. HYDRAULIC PUMP.

yi ai acre,

' Speccation of Letters Patent.

Patented June 6, 1922.

application mea inareh 27, 191e. serial No. 285,690.

To Il whom #may concern:

\Be it known that I, ROBERT EsNAUL'r Pnurmun, a citizen of 4the Re ublicof Franc-@residing in the city of aris, Republic of `France, haveinvented certain new ,and useful Improvements in Hydraulic Pumps, ofwhich thel following is a specilication. y

The present invention has for its object a hydraulic pump working atvery high` pressures with no matter what liquid, either as a transmitteror as a receiver of power, ac-

cording' as it` has furnished to it mechanical v energy which ittransforms into a supply of liquid at high pressure, or is supplied witha liquid at high pressure and which it returns as mechanical energy.

This pump orf-motor principally comprises any-number of cylindersarranged symmetrically around the general axis of the machine with theirindividual axes parallel withthe said general axis.

These lcylinders act upon the shaft' which is to furnish the'v power, bybearing upon an annular plate the axis of which represented makes anacute angle withthat of the shaft which is' to furnish the power, thisbearing being efi'ectednthrough the medium of a further annular membercalled a cap which presses the plate through the medium of a ball stop.j

The cap is on the other hand prevented .from rotating by a suitabledevice which will be described, of such a kind that its movement isreduced to a movement of nuta- V tion.

rlhe whole of this arrangement has been long known and forms part ofpublic property, but the presentinvention is specially characterized bythe manner in whlch this system is carried out, which both permits ofgreat strength, greatlightness and an ex.- cellent mechanical eiiciency.

The most particular points thereof are:

1. The arrangement-of the pistons which permits veach one of'them toserve as a distributing slide valve to one of the others.

2. The suppression of connecting rods and their replacement by ballswhich yare sub- 'ected to a very peculiar movement -as will e'hereinafter explained.

3. The fixation of the angular situation of.

The accompanying figures, which show,

by way of example, a method of practically carrying out the invention,will make the working of this pump properly` understood, they relatemore especially to its application as a receiver, but it will suiiice'simply to invert the distribution in order to make it play the .part ofa generator of liquid under pressure. I

Flgure l represents a genera-1 yview of the motor in axial section.l 1

Figure 2 represents a' graphic view of the movement of the pistons,.indicating the arrangement by which it is possible to make each of themserve as a slide valve to one f.

cations which connect ythem with each other.

re 4 represents, on a large scale, one` of the. balls which serve totransmit the pres- Figu sure of the piston to the oscillating cap.

Figure 5 represents a modification of this arrangement.l i The shaftwhich is to receive the` movement and transmit the power isl composed ofa cylindrical member a the outer end of which serves to transmit orreceive the movement and the inner end of which carries an inclinedblate b which itself supports the race c of the two stop balls d, d',

which are shown in Figure 1, and of which theY other race e, constitutesthe cap above mentioned. `This cap carries a number of bosses f equal tothe number of the pistons,

as well as a conical outer extension which is terminated by a conicaltoothed portion or pinion L engaging with van identical toothed fportion z' which is centered and keyed on the xed body y' of the motor.

If we call 6 the angle which the axis of the inclined plate b makes withthe general axis of the motor, the two conicalplmons above mentionedmust obviously, to be identical,

each have a total opening at the apex, equal mre-9) he oscillating cap eis, furthermore, maintained concentrically on the shaft O a by a set ofballs c.

It will be easily understood that under these conditions that when theshaft a rotates about the axis (l as the plate b `inclined upon it tendsto compel the cap eto' follow its movement.

Since this latter cannot rotate by reason of the action of the pinions kand i, it is compelled to accomplish a movement of natation and thebosses f thus remain constantly opposite the orifices of each .of thepistons, While yet moving longitudinally.

If therefore, this pump were to serve to force back a liquid underpressure when the shaft a were rotated, the pistons Z would receive,through the medium ofV their individual ball, m, an alternate movementof amplitude determined by the inclination of the plate b and by itsradius.-

In the case in which the pump is to serve as a motor, the liquidpossessing an initial l which the pistons exert only takes place onl oneof the halves'ot` the plate b of which they also produce the rotationand conscquently that of the shaft a Which is connected to it.

-The initial pressure may obviously be re placed or assisted byhelicalsprings of a uitable kind, seated in each piston cham- Themovement of theL balls m, which is a little complicated, will beexplained later on.

The total pressure which is exerted on the stop ZZ, is, on the otherhand, received by the ball stop n.

ihe centrifugal forces dueto the decentering of the plate Y) and of thering c, and also the forces of inertia due to the balls d, d, to themovement of nutation of the cap and of its bosses f, its extension g andits pinion 7L and also to the alternate movements of the pistons Z arecounterbalanced by a suitable mass 0 which is easy, to the personskilled in the art, "to determine, for each type of apparatus after allthese data are known.

As the applicant has more especially endeavoured to effect rst andJforemost a. realization of the invention applicable to air craft, thepresent pump, as described, comprises various arrangements intended toconfer upon it great lightness, but these particular arrangements aregiven by Way of example only and in no way limit the invention which mayalso be equally Well applied to industrial realizations which have noneed of lightness. Y

The oil under pressure arrives by the central pipe p which carries onits inner end an expanded portion which allowsthe oil to reach that partof each cylinder ,which serves as a slide valve for one of the others,as will be hereinafter explained.

In order to simplify the figure, the piston packing fr lhave bee/nshovvn'diagrammatically. They may ith advantage be constituted b thesystem of metallic packing which t e applicant ha/s patented in GreatBritain under No. 107 ,760, dated the 20 June, 1917, and which.areparticularly adapted to the applications to high' pressure liquidpumps.

They may, oi' course, be constituted as in anv ot-herA fluidtightsystem.

ln Figure 1, the piston Z is shown at the right hand `end of its strokearfd it Will be seen that in this position the circular groove mthereinputs the oil su pipe p and 'its expanded portion g iii/ocommunicationvvith the Working chamber of another piston Athrough themedium of the passage s. The piston Z is shown-in the extreme inverseposition and it willA be see-n that it also puts the orifice s of thepiston Bfpr which it serves as a slide valve, into communication withthe annular space t communieating With the exhaust pipe u.

There'vvill also be seen in this figure the ends fv, o of the passageswhich cause the chambers of the pistons Z'and Z to communicate withthose which respectively servo them as a slide valve.

To prevent thepressure in the chambers from Aaccidentally exceeding thepressure which exists in the inlet pipe p (or the force pipe,if the casebe that of a generator) safety valves or balls .1," are arranged on eachof these chambers.

The valve gear will be Ifoperly understood by the following consierations:

Figure 2 is a graphic i'reW in which the n abscissae represent the tunesor the angular l movements of the motor shaft, and ,ordihates, theelongations of the pistons, with respect to their mean position.

The sinusoid in full lines represents the elongations of piston No. 1, Zfor example, and for the simplfication of the figure. there have onlybeen shown, for the other pistons, certain apexes of their respectivesinusoids, each bearing` its number. The pistons thus act inthesuccessive order of numeration andthe pump is supposed to act as ahydraulic motor. l.

With the central inlet and the external circular delivery, thearrangement of cm-v municating passages from piston to piston.necessitates that, when in the loW position, each piston shall cause theone which it controls to communicate with the inlet, and in the highposition with the delivery.'

If in certainA applications it is deemed preferable to use the externalconnection as 4an inlet, and the internal connection as a delivery, thepassages communicating with the cylinders must be appropriatelyrearranged. Y

In the one which has been adopted, it

will be understood after examining Figure temeva 2, that iston No. 1,must be controlled by piston o. 8, which plays in relation to it thepart of a slide valve, and establishes the communications in the mannerrepresented by the lines OA, FA, andOR, FR, the ends of which correspondrespectively to the opening and closing of the inlet and delivery. Inthe reverse case, the aforesaid piston No. 1, must be controlled by No.3.

If the pump acts as a generator, the arrangements of distribution aboveindicated, must both be reversed. It will be easy to the person skilledin the art to get a clear idea of these various arrangements from thepreceding explanation.

Figure 3 represents the-successive pistons Z, Z2, Z3, Z4, Z5' which aresupposed to `be developed on the plane of the ligure, as well as theinlet pipe p and the force pipe 1f diagrammatically represented in atubular Jform.

In this figure will be found thel orifices g which cause each piston tocommunicate, by that part which acts as a slide valve', with the inletpipe and also theorifces and passages s, o, which cause each slide valvepiston to communicate with the chamber of the 'one which itcontrols.

In the real arrangement of Figure 1, all these communications areconstituted by holes suitably located and bored' in the mass itself otthe motor, so as to causethedesired cavities to communicate with eachother.

The working of the stop balls of the pis-f tons takes place as will nowbe described.

Figure 4 represents, on a large scale, the position of one of the ballsm between the piston Z, which it operates, and the boss f ofthe cap e.

For the sake of greater clearness in the description, the long,ritudinalv move-ment of the piston will at first be omittedf and itwill be admitted that Vthe boss f is conical about the axis O, Z, whichforms with the axis O, Xian angle equal tothat which has been mentioned.v

It will be supposed under these conditions, that the boss f accomplishessimply a movement of mutation, that is to say thatits axis O', Z rotatesabout the axis O', X,

with a uniform movement, but that by any suitable arrangement, theangular position of the boss f in space does not vary.

lllder theseconditions if the cone which constitutes the boss f has atotal ope-ning equal to (1r-1: 0) that is to say it the geometrical axiso) o: is parallel with the plane a', 'o of the end of the piston, ltheballA will be constantly pressed against this piston end and avgeometrical axis cx" of the boss f which remains. constantly parallelwith the plane o', fu. f K' v The ball' does/not thereiore tend toescape Zand experience showslthatifthe point Q is suitably placedbyadjustment to the vicinity of the surface o', e the ball takes up aposition of equilibrium for which its point of contact describes aboutthe centre m of the piston, a circle of a radius t) while its 0therpointof contact v describes on the cone a circle of a radius v e nearly equalto `the rst one. rIhe ball ceases then to rotate upon itself, or atleast is only subjected to an extremely reduced movement. 4

Experience proves likewise that if the cap j rotates as a whole aboutO', X in place of ,following the movement of nutation which has beenindicated, the ball has no stable position and escapes on the side. Itis now comprehensible that if the axis O', Z of the boss, in place ofbeing the axis of nutation proper is located as in Figure 1, outsidethis axis, the movement just described subsists but there is addedthereto a longitudinal movement corresponding to its elongations whichare the greater the further the axis of the boss is from the axis ofnutation, this distance allowing the stroke which it is desired toobtain for the pistons p \to be regulated.

To diminish the wear of the balls, it may be favourable to replace theconical cap of the bosses f'by avspherical cap as shown in Figure 5. p

In this case, it .suffices that the centre of this spherical cap belocated at the point of -intersection O (see Figure 4) of the secondaryaxis of 'nutationA O', Z and of'the diameter which joins the two pointsof contact of the ball. It is also possible to make inthe face of thepiston a race in the form of a torus, as shownin the upper part ofFigure 5.

When I speak in my claims of a shafti I mean to include both anactuating an receiving shaft depending upon whether the device is usedas a pump or motor; and when .I speak of my device as being adapted foruse as a pump I also mean that it can be used as a motor.

What I claim` and desire to `secure by i Letters Patent of the UnitedStates is':-

1. A hydraulic power transmlttlng device comprislng a Casin a shaft insaid'casing, a plurality of cylinders, a piston in each cylyinder, .amember secured to said shaft hav` ing.v an operating surface inclinedwith re spect thereto, an annulaimember located between said pistons andsaid operating sur-v face and serving as a motion transmitting means,means to prevent rotation of said annular member but permitting amovement of nutation thereof, and free balls located between saidpistons and said annular member as a means for transmitting motiontherebetween.

2. A hydraulic power transmitting device comprising a casing, a shaft insaid vCasin a plurality of cylinders, a piston in eac cylinder, a'member secured to said shaft Cri 'having an 'operating surface inclinedwith respect thereto, an annular member located between said pistons andsaid operating surface and serving as a motion transmitting means, meansto prevent rotation of said an` nular member but permitting a movementof nutationv thereof, rollers forming an .antifriction bearing betweensaid annular member and said operating surface, and free balls locatedbetween said pistons and said annular member as a means for transmittingmotion therebetween.

3. In a hydraulic apparatus, the c-ombination of a casing, a shaft insaid casing, a plurality of cylinders in said casing, a piston in eachof said cylinders, a pinion secured to said casing, an oscillating dischaving a pinion adapted to co-operate with the pinion on the casing andinclined with reference to said shaft, free balls, located between thepiston andkdisc, acting each as a connect-ing rod, an inclined platesecured to the shaft and balls interposed between the disc and plate.

4. In a hydraulic apparatus, the combination of a casing, a shaft insaid casing, a plurality of cylinders in said casing, a piston having aflat end in each of said cylinders, a pinion secured to said casing, anoscillating disc having a pinion adapted to co-operate with the pinionon the casing and inclined with reference to said shaft and havingv araceway, free balls, located between the flat ends of the pistons andraceway of the disc, acting each as a connecting rod, an inclined platesecuredto the shaft and balls interposed between the disc and plate.

5. In a hydraulic apparatus, the combina tion of a casing, a shaft insaid casing, a plurality of cylinders in said casing, a piston my name.

in each of said cylinders, a counterweighted plate secured to saidshaft, an oscillating disk, free balls, located between the piston anddisk, acting each as a connecting rod, means for preventing the discfrom turning and balls interposed between the disc and plate.

6. In a hydraulic apparatus, the combination of a casing, a shaft insaid casing, a plurality of cylinders in said casing, a piston in eachof said cylinders, a plate, an oscillating disc, free balls,`locatedbetween the piston and disc, acting each as a connecting rod means forpreventing the disc from turning and balls interposed between the discand plate.

7.In a hydraulic apparatus, the combina tion of a casing, a shaft insaid casing, a plurality of cylinders in said casing, a piston in eachof said cylinders, a plurality of couduits in said casing, each'connecting one of the cylinders with one of the other cylinders andhelically arranged to pass each other, the intersection of the conduitsand cylinders being in the form of helicoids. t

8. In a hydraulic apparatus, the combination of a casing having a highpressure pipe at its center andlow pressure pipes on its outer side, ashaft in said casing, a plurality of cylinders in said casing, a pistonin each of said cylinders, an oscillating disc, means comprisin a pinionfor preventing the disc from turnlng, free balls, located between .thepiston and disc, acting each as a connecting rod, an inclined platesecured to the shaft, and balls interposed between the disc and plate.

In witness whereof, I have hereunto signed ROBERT EsNAUL'r PELTERIF..

